Method of producing white lead.



No. 709,957. Pafenied Sept. 30-, I902.

- J. w. BAILEY;

" METHOD OF PRODUCING-WHITE LEAD.

(Application filed Mar. 14; 1901.

tribunal.)

2 Sheets-Sheet I.

ATTORNEYS WITNESSES.

m: uonms PETERS co. Moro-Limo WASHINGTON. n. c.

Patented Sept. 30, I902. J. W. BAlLEY NIETHUD 0F PRODUCING WHITE'QLEAD.

(Application filed Man 14, 1901.

*2 Sheets-Sheet 2.

(N0 Modei.)

IINVENTOR WITNESSES KW EKW ATTORNEY UNITED STATES ATENT OFFICE.

JOHN T. BAILEY, OF JERSEY CITY, NEW JERSEY, ASSIGNOR TO UNION LEAD AND OIL COMPANY, A CORPORATION OF NEW JERSEY.

METHOD OF PRODUCING WHITE LEAD.

SPECIFICATION forming part of Letters Patent No. 709,957, dated September 30, 1902. Application filed March 1 1, lQQl. Serial No. 51.150. (N specimens.)

T0 at. whom, it may concern:

Be it known that I, JOHN W. BAILEY, acitizen of the United States, and a resident of Jersey City, in the county of Hudson and 5 State of New Jersey,have invented a new and Improved Method of Producing Lead Carbonate, of which the following is a specification.

My invention relates to a method of manufacturing or producing lead carbonate,or the to white lead of commerce.

More particularly, myinvention consists in a new and improved method of corrosion whereby metallic lead is wholly converted without waste into an entirely amorphous product of perfect opacity and great purity and in a very short time as compared with the most approved mode of corrosion hitherto employed.

In the methods heretofore devised for the manufacture of white lead from metallic lead by corrosion or by What is known in the art as the Dutch process the metal, although in a comminuted condition, has been introduced into the corroding-chamber in pieces orparticles of such size that the time required to completely corrode the same is quite considerable, in some cases days and in other cases weeks being required to completely corrode a single charge of metal. In the old methods, moreover, the charges of metallic lead are necessarily formed of a mass or masses of the comminuted metal. The metal in these masses is inevitably unevenly exposed to the corrodinggases, not only by rea- 5 son of the fact that the metal forming theinner parts of the masses is more or less protected from t'neaction of the gases by the metal forming the outer parts of the masses, but also because the entangled fibers or fila- 0 ments forming the masses unavoidably become more or less matted or compacted, and unevenly so, owing to the-very soft character of the metal and thelack of any definite structure in the masses. The result is that the 5 lead has to be subjected to the action of the corroding-gases a much longer time than would otherwise be required to completely corrode the metal, and by reason of the lack of unitormityin the masses local aggregations of uncorroded metal are apt to remain, and the product not only lacks homogeneity, but

requires special treatment for the separation of the metallic residue.

My invention has for an object to provide a method for the manufacture of white lead in the practice of which the use of the masses of com minuted lead referred to,together with the complicated and troublesome and expensive machinery required to handle the same,is entirely done away with; also, to provide a method whichwhile involving the use of the same elements employed in corroding by the old Dutch process and producing a similar product requires much less time to complete the various steps and less expense and less manual labor than are required by any method heretofore devised and which produces, nevertheless, a product which is less contaminated with stains and impurities and has greater covering and spreading qualities-than that produced by any prior method.

More particularly, myinvention has for an object to obtain, as nearly as may be, those conditions most favorable to the combination or chemical union of the elements required for the production of the desired product,

and to maintain those conditions for an indefinite time, thus. rendering the practice of the method automatic and continuous at all stages of the manufaoture,from the metallic 8 lead to the completely-corroded product.

In accordance with my invention themetallic lead is first pulverized or otherwise disintegrated and reduced to a fine condition, and then it is diffused'in a suit-able corroding-gas.

My invention also consists in pulverizing the lead and then subjecting it to the action of suitable corrodinggases, the lead being in such a fine state of division that when the corroding action has once begun on a particle the entire particle will be corroded.-

It is also in accordance with my invention that the metallic lead is pulverized or otherwise disintegrated and reduced to the form 5 of an impalpable powder and then subjected to the action of a suitable corroding gas or gases.

In accordance with the best embodiment of my invention I put metallic lead which has previously been granulated or otherwise comminuted to a suitable degree of fineness into a pulverizing-mill adapted to reduce the lead in a dry state to a fine dust or impalpable powder, such as may be floated in and conveyed by a suitable current or blast of air or other gas. This powder is then subjected to the action of suitable corroding-gases. The best results are attained, both as to acceleration of the corroding process and as to the quality of the product, when the lead is reduced to such a fine state of subdivision that when in the corroding-chamber substantially all the lead is at once exposed to the action of the corroding agents.

Although my invention in its broader aspects is not limited to the particular manner in which the finely-divided lead is subjected to the action of the corroding-gas, the best mode in which I have contemplated carrying out this feature of the process consists in diffusing the pulverized lead throughout a body of a suit-able corroding-gas and maintaining this diffused condition until the corrosion of the metal is complete, or so nearly so that it will continue and become complete after the diffused condition has ceased. This step may be accomplished by introducing the powder, preferably in the form of a stream or current of dust-laden air or air and other gases, into a corrodiug-chamber in which a current or circulation of the corroding-gas is maintained, so as to diffuse the powder in the gas and maintain it in the diffused condition for such length of time as is required to insure the corrosion of the metal. According to the preferred form of procedure a whirling motion of the corroding-gas is maintained in the corroding-chamber, whereby the powdered lead may be floated and kept afloat or in a state of suspension for an indefinite time.

In the accompanying drawings, which are referred to herein and form a part hereof, two forms of apparatus adapted to carry out my improved process are illustrated for the purpose of more clearly explaining the principles of my invention and defining its scope.

In the drawings, Figure 1 is a sectional diagrammatic View illustrating the preferred form of apparatus invented by me for carrying the process into effect. Fig. 2 is a plan View of the same; and Figs. 3 and 4 are views similar to those of Figs. 1 and 2, respectively, illustrating another form of apparatus adapted to carry out my invention.

Like reference-numerals refer to like parts wherever they occur throughout the several views.

Referring now to the drawings in detail, and more particularly at first to the form of the device shown in Figs. 1 and 2, 1 represents a pulverizing or disintegrating mill, such as is adapted to reduce the metallic lead to the desired degree of fineness. This mill may be of any ordinary construction. As shown, it comprises a cylindrical chamber to the inner walls of which are fixed a plurality of inwardly-extending fingers or bars 2, between which the radial fingers or bars 3,

carried by a central shaft 4, are adapted to rotate. The shaft 4 is suitably journaled in the heads 5 of the cylinder and is provided with a driving-pulley 7, by means of which it may be given a Very rapid rotation. A hopper 8 is provided at one end of the cylinder, through which lead in a suitablycomminuted condition may be introduced into the mill. An outlet-passage 9 is provided at the opposite end of the mill, through which the powder or dust formed in the mill may be withdrawn. In the form of apparatus shown the outlet 9 is connected with the inlet-passage of a suitable fan or blower 10, the outlet-passage of which is connected by pipe 11 to the inlet-passage 12 of a corroding-chamber 13. The corroding-chamber 13 is preferably in the form of a cylinder vertically arranged with the inlet-passage 12 located at or near the top. The inlet-passage 12 is preferably arranged to communicate with the chamber 13 in a tangential direction, so as to create and maintain a circular or rotary movement of the air and gases in the cylinder, the object being to keep the powdered lead in a state of suspension and to create a zone in the center of the chamber which is comparatively free from the dust-particles. The bottom of the chamber 13 is made in the form of a hopper 14:, so as to enable the corroded metal which collects in the bottom to be withdrawn from time to time through a suitable outlet-passage 15, a gate-valve 16 being provided to facilitate this operation. The outlet-passage 1'7 for the corroding-gas is arranged at the center of the top of the chamber, and where a single chamber is used this outlet is covered by a screen of cloth or other material adapted to permit the escape of the gas and not the dust. Preferably, however, I employ in addition to the chamber 13 one or more supplementary chambers to complete the corrosion of the particles not corroded in the first chamber. Two such additional chambers 18 and 19 are shown. Where a third chamber is used, the second chamber may be identical with the first chamber, and its inlet-passage will be connected with the outlet for the gas of the first chamber. As shown, the inlet-passage 20 of the second chamber is tangentially arranged, and the chamber is provided at its bottom with a hopper 21, the outlet of which is controlled by a gate-valve 22. The last chamber 19 of the series has a tangential inlet-passage 23, which communicates with the outlet for the air and gases of the preceding chamber, and this chamber is also provided with a hopper-shaped bottom 24: and a valve 25. The top of this chamber is covered with a screen 26, which consists of bolting-cloth or other material adapted to permit the escape of the gases and retain the particles of dust. The gases and vapors necessary to effect the corrosion of the powdered lead may be supplied to the chambers in any suitable way. In the construction shown an injector IIC 2'7 is provided for this purpose, and it'is preferably connected with the inlet-passage 12 of the first corroding-chamber 13. This injector comprises an inlet-pipe 28, which is preferably connected with a steam-generator in order to supply the heat and moisture required in the process of corrosion and to create a suction by means of which the carbonic-acid gas and vapors of acetic acid, also required for the corroding process, maybe drawn in, a pipe 29, connected with any suitable generator, being provided to supply these gases. The process may be carried out with this apparatus in the following manner: The mill 1 and the blower 10 having been set in motion and the supply of steam and carbonic-acid gas having been established, granulated or other finely-divided lead is fed into the mill 1 through the hopper 8, and as fast as the lead becomes fine enough a stream or current of it is drawn from the mill with the current of air created therein by the blower 10. This current of dust-laden airis brought into contact with and intimately commingled with the current of corroding-gases in the inlet-pipe 12, and this mixture is forcibly blown into the corroding-chamber 13 by the steam-jet and the blast from the blower 10. A rapid circulation of the air and gases in the chamber 13 is thus created and the particles of powdered lead are thoroughly diffused throughout these gases andheld in a state of suspension or floated therein for a considerable length of time. As the particles begin to corrode they gradually settle toward the bottom of the chamber, where the process of corrosion, if not already complete, will continue as long as the apparatus is kept in operation or until the metal is entirely corroded. Where a second corroding-chamber is used,a considerable portion of the powdered lead will escape through the outlet 17 of the chamber 13, together with the gases, and will be carried thereby into the second corroding-chamber, where the corroding process will continue, this operation being repeated through the successive chambers until the tinal separa tion of the air and gases by means of the screen which covers the outlet of the last chamber. As many chambers of course may be used as circumstances may require. It will be seen that the portion of the metal which passes through two or more of the corroding-chambers will be subjected to a series of successive currents of the corroding-gas and will be kept in a state of suspension for a longer time than if it passed through one chamber only. The corroded product may be removed from the bottom of the corrodingchambers from time to time as it collects therein, and then washed and dried in the usual manner to prepare it for the market.

Another form of apparatus by which my invention may be carried into effect is shown in Figs. 3 and 4. According to this construction the finely-divided lead is sifted or diffused in the top of a vertical corroding-chamber in such a manner as to produce a downwardly-moving current of the metal, through which an upwardly-flowing current of the corroding-gas is maintained. In this apparatus the particles of lead as they fall through the chamber are subjected to the action of the corroding-gases in such manner as to insure the completion of the corroding action, the final product beingremoved' at the bottom. In the construction shown a vertical corroding-chamber is provided and is preferably constructed in the form of a chimney or tower 30, which may be of any desired height, it only being important to note that the finer the metal is divided and the stronger the current of the corroding-gas the shorter the corroding-chamber may be. A suitable receptacle 31 for the powdered lead is arranged at the top of the corroding-chamber, and in the construction shown this receptacle is provided at its bottom with a series of outletpassages 32, which are carried into and arranged in a parallel relation across the top of the corroding-chamber. Each of the passages 32 is provided within the corrodingchamber with a series of perforations 33, through which the powdered lead is uniformly sifted by a suitable conveyer located within the passage. These conveyors, as shown, consist of suitable worms 34, which are extended across the bottom of the receptacle 31 and are driven by any suitable means, as the pulleys 35. The corroding-gases for the corroding-chamber are supplied through a pipe 36, which is carried around the corrodingchamber at the bottom thereof and is provided with a series of jet-pipes 37, which enter the bottom of the corroding-chamber from all sides. A suitable blast may be created through this pipe by any suitable means, as by a blower and steam-jet, such as illustrated in connection with the form of the apparatus previously described. The corroding-chamber is provided at the top with a screen 38, which will permit the escape of thecorroding-gases and prevent the escape of any particles of lead which may be carried along therewith. The corroding-chamber is provided with a hopper-shaped bottom 39, the outlet of which is controlled by a-suitable gate or valve 40. My invention may be carried out by means of this apparatus as follows: A suitable blast of air and corroding gases or vapors having been established through the pipe 36 and a supply of powdered lead having been placed in the receptacle 31, the worms or propellers 34 are set in motion, and the powdered lead is thus conveyed into the top of the corroding-chamber and diffused throughout the corroding-gas therethe current of gas in the chamber it is subjected to the action of the corroding-gases, and the corroded product is collected in the hopper at the bottom of the chamber, from whence it may be removed from time to time By reason of the and prepared for market.

As the metal falls downwardly throughv upward current of the corroding-gas in the chamber the fall of the metal is more or less retarded, and in this way it maybe floated and maintained in a diffused condition in the gas, so that it can be uniformly acted upon thereby for a length of time suificient to insure the completion of the corrosion. The fineness of the screen 38 and the strength of the blast through the supply-pipe 36 are so regulated as to maintain a suitable pressure of the corroding-gas in the corroding-chamber.

Instead of discharging the corroding-gas from the the top of the corroding-chamber 38 into the air it obviously may be conveyed to a second or any desired number of successive corroding-chambers, a suitable means for supplying each of the chambers with powdered lead of course being provided.

It is among the advantages of my invention that the corroding process may be carried out very rapidly and by a simple apparatus which is automatic and continuous in operation and may be easily and accurately controlled. All poisonous gases and other substances are securely confined within the apparatus, and the injurious etfects to the workmen which are incident to the forms of apparatus heretofore constructed are thus entirely removed.

My process may obviously be carried out by numerous other forms of apparatus, and Ldesire it to be understood, therefore, that my invention in its broader aspects is not limited to the particular methods of procedure herein shown and described nor to any particular mode of proced ure by which it may be carried into effect, as many variations may be made therein without departing from the main principles of my invention and Without sacrificing the chief advantages thereof.

The apparatus shown and described herein is not herein claimed, as it forms the subjectmatter of another application for a patent filed by me simultaneously herewith, Serial No. 51,149. The powdered lead, moreover, and the method of and apparatus for making the same which are shown and described herein are not herein claimed, as the same form the subject-matter of other applications for patents, said applications being numbered 113,213 and 113,214 and dated June 25, 1902.

Having described my invention, what I claim, and desire to secure by Letters Patent, 15-- 1. The method of producinglead carbonate, which consists in subjecting lead in the form of an impalpable powder to the action of a suitable corroding-gas, substantially as described.

2. The method of producing lead carbonate, which consists in subjectinglead in the form of an impalpable powder to the action of a current of a suitable corroding-gas, substantially as described.

The method of producing lead carbonate, which consists in diffusing pulverized or powdered lead in a suitable corroding-gas, sub stantially as described.

4. The method of producing lead carbonate, which consists in diffusing pulverized or powdered lead in a current of a suitable corroding-gas, substantially as described.

5. The method of prod ucinglead carbonate, which consists in floating pulverized or powdered lead in a suitable corroding-gas, substantially as described.

6. The method of producinglead carbonate, which consists in floating pulverized or powdered lead in a current of a suitable corroding-gas, substantially as described.

7. The method of producing lead carbonate, which consists in diffusing pulverized or powdered lead throughout a suitable corrodinggas confined in a closed chamber and creating a circulation of the gas in the chamber, substantially as described.

8. The method of producing lead carbonate, which consists in subjecting lead in the form of an impalpable powder to the action of a series of successive currents of a suitable corroding-gas, substantially as described.

9. The method of producing lead carbonate, which consists in floating pulverized or powdered lead in a suitable corroding-gas by means of a series of successive currents of said gas, substantially as described.

10. The method of producing lead caroonate, which consists in reducing lead to an impalpable powder and then subjecting it to the action of carbonic-acid gas and acetic acid in the presence of air and moisture, substantially described.

11. The method of producing lead carbonate, which consists in reducing lead to an impalpable powder and then subjecting it to the action of a corroding-gas composed of air, carbonicacid gas, and vapors of acetic acid and water, substantially as described.

12. The method of producing lead carbonate, which consists in reducing lead to an impalpable powder and then floating the powder in a corroding-gas composed of air, carbonicacid gas, and vapors of acetic acid and water, substantially as described.

13. The method of producing lead carbonate, which consists in dividing the lead into a fine condition producing a current of said finely-divided lead, and bringing said current into contact with a current of a suitable corroding-gas, whereby the lead is diffused throughout said current of gas and thoroughly exposed to the same, substantially as described.

14. The method of producing lead carbonate, which consists in pulverizing the lead passing a current of air through the pulverized lead so as to carry away the particles of lead that are fine enough to float in said current, bringing said current into contact with a current of a suitable corroding-gas, and causing the combined currents to inter-mingle and circulate together in a suitable chamber, substantially as described.

IIO

15. The method of producing lead carbonate, which consists in pulverizing the lead passing a current of air through the pulverized lead so as to carryaway the particles of lead that are fine enough to float in said current, bringing said current into contact with a current of a suitable corroding-gas, and

causing the combined currents to intermingle and circulate together in a suitable chamber, and filtering the gases as they escape from the chamber so as to prevent the loss of lead, substantially as described.

16. The method of producing lead carbonber so as to produce an area of less disturb-.

ance in the middle of the chamber and leading off the waste gases from the middle portion of said chamber, substantially as described.

17. The method of producing lead carbon ate, which consists in pulverizing the lead, passing a current of air through the pulverized lead so as to carry away the particles of lead that are fine enough to float in said current, bringing said current into contact with a current of a suitable corroding-gas, and causing the combined currents to circulate around the outer portion of a suitable chamber so as to produce an area of less disturbance in the middle of the chamber and leading off the waste gases from the middle portion of said chamber and filtering the gases as they escape from said chamber, substantially as described.

18. The method of producing lead carbonate, which consists in subjecting powdered lead to the action of suitable corroding-gases, the lead being in such a fine state of division that when the corroding action has once begun on a particle the entire particle will be corroded.

19. The method of producing lead carbonate, which consists in subjecting powdered lead to the action of carbonic-acid gas, air and the vapors of acetic acid and water, the

lead being in such a fine state of division that when the corroding action has once begun on a particle the entire particle will be corroded.

20. The method of producing lead carbonate, which consistsin diffusing powdered lead throughout a suitable corroding-gas, the lead being in such a line state of division that when the corroding action has once begun on a particle the entire particle will be corroded.

21. The method of producing lead carbonate, which consists in diffusing powdered lead in a corroding-gas consisting of air, carbonic-acid gas and the vapors of acetic acid and water, the lead being in such a fine state of division that when the corroding action has once begun on a particle the entire particle willbe corroded.

22. The m thod of producing lead carbonate, which consists in subjecting powdered lead to the action ofsuitable corroding-gases, the lead being in such a line state of division that substantially all of the lead is at once exposed to the action of the corroding-gases.

23. The method of producing lead carbonate, which consists in subjecting powdered lead to the action of carbonic-acid gas, air and the vapors of acetic acid and water, the lead being in such a fine state of division that substantially all the lead is at once exposed to the action-of the corroding-gases.

24. The method of producing lead carbonate, which consists in diffusing powdered lead throughout a suitable corroding-gas, the lead being in such a fine state of division that substantially all the lead is at once exposed to the action of the corroding-gas.

25. The method of producing lead carbonate, which consists in diffusing powdered lead in a corroding-gas consisting of air, carbonic-acid gas and the vapors of acetic acid and Water, the lead being in such a fine state of division that substantially all the leadis at once exposed to the action of the corroding-gas.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOHN W. BAILEY.

Witnesses:

PENNINGTON HALSTED, EDWIN Susan. 

